1. Field of Invention
The present invention relates to a mount bushing of a stabilizer bar applicable to a suspension system of a vehicle. More particularly, the present invention relates to a mount bushing of a stabilizer bar for a vehicle that enhances marketability and fuel economy of the vehicle by reducing noise and friction and improves durability by preventing foreign materials and grease respectively from flowing into or flowing out.
2. Description of Related Art
A stabilizer bar of a vehicle is applied to an independent suspension system, and is a type of torsional springs that secures balance of a vehicle body by suppressing roll motion of vehicle body when the vehicle turns or drives on a rough road.
FIG. 1 is a top plan view of a suspension system for explaining structures of a conventional stabilizer bar.
Referring to FIG. 1, both ends of the stabilizer bar 2 are respectively connected to lower control arms 8 and 10 or strut assemblies 12 and 14 through control links 4 and 6.
In addition, both side portions of a middle linear portion of the stabilizer bar 2 are fixed to a sub frame 16 through mount bushings 18 and 20.
The stabilizer bar 2 described above operates as an auxiliary spring that supports left and right wheels when the vehicle body rolls. When the left and right wheels move with the same phase, a force is not applied to the stabilizer bar 2. When the left and right wheels, on the contrary, move with different phases, the stabilizer bar 2 restricts movements of the left and right wheel by torsional elastic force so as to suppress the roll of the vehicle body.
For example, the stabilizer bar 2 applies elastic force to the both wheels so as to synchronize movements of the both wheels when the vehicle turns (i.e., when the outer wheel to a turning direction bounds and the inner wheel to the turning direction rebounds). Therefore, the stabilizer bar 2 suppresses tilt of the vehicle body. On the contrary, the stabilizer bar 2 does not apply the elastic force when the both wheels move to the same direction.
In addition, the conventional mount bushing 18 and 20 that fixes the both side portions of the middle linear portion of the stabilizer bar 2 to the sub frame 16 is shown in FIG. 2 and FIG. 3.
FIG. 2A is a cross-sectional view of a mount bushing of lubrication type.
Referring to FIG. 2A, the mount bushing 18 and 20 of lubrication type includes a bracket 22 and a rubber bushing 24 to which lubrication ingredient is added, and the bracket 22 is fixed to the vehicle body or the sub frame 16 in a state of enclosing the rubber bushing 24.
The stabilizer bar 2 having a circular cross-section penetrates through and is fixed to a center portion of the rubber bushing 24. Therefore, the rubber bushing 24 reduces noise or vibration caused by movements of the stabilizer bar 2. In addition, the rubber bushing 24 affects on roll strength according to compression force to the stabilizer bar 2.
FIG. 2B is a cross-sectional view for explaining development of minute deformation of I region in FIG. 2A.
Referring to FIG. 2B, if the stabilizer bar 2 rotates by about 2°-3° in the mount bushing 18 and 20 of lubrication type, the rubber bushing 24 begins to deform and then is slipped.
If the rubber bushing 24 is slipped, noise occurs. Particularly, as the rubber bushing 24 becomes aged, the noise get louder.
FIG. 3A is a cross-sectional view of a mount bushing of double steel type.
Referring to FIG. 3A, the mount bushing 18 and 20 of double steel type like the mount bushing of lubrication type includes the bracket 22 and the rubber bushing 24, and a double steel bushing 26 is inserted in the rubber bushing 24. When the stabilizer bar 2 rotates, the mount bushing 18 and 20 of double steel type uses the double steel bushing 26 so as not to occur slip.
FIG. 3B is a cross-sectional view for explaining development of minute deformation of II region in FIG. 3A.
Referring to FIG. 3B, since slip does not occur in the mount bushing 18 and 20 of double steel type, noise problem can be solved. However, rotating torque increases proportional to a rotation of the stabilizer bar 2. Therefore, friction may increase and fuel economy may be deteriorated in a case that the vehicle moves excessively.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.